Things did not quite go to plan when two towers were blown up for charity.

Spectators who gathered to watch the demolition at Desford Steel Tubes factory, in Desford, could not believe their eyes when the 150ft towers remained standing – despite huge explosions and billowing clouds of dust.

Eventually cranes had to be used to push over the unstable towers and send them crashing to the ground.

John Woodward, site co-ordinator of AR Demolition, said: "This has never happened before, we've never even had one tower standing after a blast.

"The odds of one tower remaining up is 100 to one, the odds of that happening to two towers is about 10,000 to one."

Yesterday's event had been staged to raise money for the breast cancer unit at Leicester General Hospital.

More than 2,000 people turned up to watch the event. Organisers sold thousands of raffle tickets throughout the morning, with the winner getting the chance to press the red detonation button, which was supposed to destroy one of the buildings.

The winning ticket was bought by Phil Beesley, 38, from Shearsby.

As he watched the tower stay upright after pressing the red button, he joked: "I'm going to get some stick for that!"

Richard Doleman, director of AR Demolition, organised the event after his wife, Kellie, was diagnosed with breast cancer eight weeks ago.

He said: "The demolition has been scheduled for a while now but the news of Kellie's cancer was a complete shock and I thought we could do something to make a bit of money for the hospital.

"It's a shame that the towers didn't go, but I'm not too bothered.

"The real focus of today was to raise money."

Yesterday's event raised more than £4,000 for the hospital. More than 700 women visit the breast cancer unit for treatment every year.

Kellie had reconstructive surgery in August and will undergo chemotherapy in about four weeks.

She said: "It was a shock to find out that I had cancer and it was on our wedding anniversary too.

"The staff at the General have been fantastic and I can't thank them enough.

"I hope that the money we raise today goes a small way to helping others in my situation."

Engineers later inspected the rubble after the towers fell.

Speaking to the Mercury yesterday, Mr Woodward said the towers may not have fallen because only half of the 14 kilos of explosives on them had detonated.

The towers at Desford Steel Tubes, in Desford Road, were the last parts of an old factory to be demolished.